Patients with posttraumatic stress disorder (PTSD) and sub threshold PTSD present to primary care clinicians (PCCs) at rates similar to depression. The estimated lifetime prevalence of PTSD is 7.8% in the general population and is higher for underserved populations that are at greater risk for PTSD resulting from interpersonal, political, and community violence. Moreover, PTSD is poorly detected, under-treated, and debilitating. But, unlike the maturing field of depression in primary care with successful quality improvement interventions, little is known about effectively treating PTSD in this setting. We will employ a theory-based multi-level framework for guiding the first step in a program of research geared toward the development of primary care-based interventions for PTSD. We plan to follow with a full-scale effectiveness study application based on the results of this proposed work. We propose an exploratory study (R34) to better understand primary care trauma management and to identify promising strategies for improving the care of adult Latino immigrant patients suffering from PTSD and sub threshold PTSD. We will conduct this research in collaboration with the Clinical Directors Network, Inc. (CDN), a community-oriented practice-based research network that provides primary and preventive health care services for poor and underserved minority and immigrant populations. Specifically, we aim to:1. Describe primary care for PTSD and sub threshold PTSD from multiple stakeholder perspectives (medical directors, PCCs, and patients) among a sample of community/migrant health centers (C/MHCs) ranging in structural characteristics, and with a high proportion of Latino immigrant patients. 2. Identify structural and individual PCC predictors of PCC tendency to screen for, assess, refer, and manage PTSD and sub threshold PTSD. 3. Elucidate potential intervention strategies, based on data from Aims 1 and 2, to develop recommendations for viable strategies that could be tested in a follow-on study to improve primary care for PTSD and sub threshold PTSD. For Aim 1, we will conduct site visits and interviews with three types of key informants from a purposeful sample of five of the 57 C/MHCs that serve Latino immigrants and refugees in one CDN region that represent a range of clinical structures that might affect PTSD care (5 medical directors, 15 PCCs, and 4 patients with current PTSD matched to each of the 15 PCCs, N=60). For Aim 2, we will formally test hypotheses about predictors of variation in treatment for PTSD with a representative survey of a census of all 57 C/MHC directors and a random sample of 285 PCCs (5 per C/MHC). Aim 3 will use Aim 1 and 2 data and stakeholder meetings to identify potential interventions most likely to improve PTSD management and will culminate with a follow-on R01 application to implement and evaluate a promising intervention program for primary care-based treatment of PTSD and sub threshold PTSD in adult, Latino immigrants.